[Investigation of anti-hypoxic action of 3-hydroxypyridine derivatives in animals with some types of experimental pathology].

Experiments with occlusion of the common carotid artery in mice demonstrated that, unlike mexidol and SK-170, single injection of new derivatives of 3-hydroxypyridine (3-HP) SK-100 and IBKhF-2, and semax have an anti-hypoxic action on the model of acute normobaric hypoxia with hypercapnia. In analogous experiments with rats the distinct anti-hypoxic action was produced by 4 new 3-HP derivatives (SK-100, SK-170, IBKhF-22 at the dose of 100 mg/kg and IBKhF-2 at the doses of 10 and 30 mg/kg--extension of life span by 25-39%), mexidol (100 mg/kg) and reference-class antihypoxant amtisol (30 mg/kg, life span expansion by 19 and 27%, respectively). A series of experiments with rats with acute pancreatitis, a distinct anti-hypoxic action was shown by SK-100, SK-170 at 100 mg/kg and IBKhF at 10 and 30 mg/kg (life span extension by 26-40%), mexidol (100 mg/kg) and amtisol (30 mg/kg) which extended life span by 17 and 22%, respectively. Therefore, SK-100 and IBKhF-2 are potent to prolong life span of equally mice and rats; SK-170 and mexidol were effective only in experiments with rats.

[Effect of acetylcholine on the structuro-functional characteristics of bush-like interoceptors of the urinary bladder of the frog]. / Vliianie atsetilkholina na strukturno-funktsional'nye kharakteristiki kustikovidnykh interotseptorov mochevogo puzyria liagushki.

In the preparation of the frog (Rana temporaria) isolated urinary bladder, it has been stated by morphological and physiological experiments that under an exogenic acetilcholine influence certain structural-functional changes take place in the bushy interoceptor. They are manifested as a sharp deterioration in coloration the receptor with methylene blue, the receptory plates decrease in their size, character of granuloformation changes in them. Simultaneously, an increased electrical activity is observed and, on the contrary, under the influence of atropine the impulse activity drops. It should be suggested that acetilcholine acts as an activator of metabolic and as a modulator of physiological processes in the receptor.

[Modality of the bush-like receptors]. / Modal'nost' kustikovykh retseptorov.

In an isolated preparation of the Rana temporaria urinary bladder after a simultaneous morphological and physiological investigation a, structural-functional differentiation of free bushy receptors has been demonstrated. According to arborization character and to the appearance of deferent fibers, the receptors are divided into two types. The first type receptors have a simple structure, a long deferent poorly branching myelin fiber, terminating in a diffuse bush near blood vessels. The second type receptors are of a more complex structure. Their myelin fibers, when leaving the fasciculus, are 4-8 times shorter than the first type receptors, undergo dichotomic and trichotomic divisions several times, and in their distal part they form two initial myelin segments. Their receptory apparatus has a tree-like bush-shaped form and consists of several compact bushes. The impulse activity of the receptors is also characterized by two types of action potentials, differing in their amplitude. When responding to a mechanical stimulation, the high voltage impulse frequency changes, when sodium chloride concentration is increased, the low voltage impulse frequency changes. There is a certain localization of the zones in the preparation from which it is possible to obtain predominantly either low voltage or high voltage responses. The response to the low voltage reaction proves to be obtained from the first type receptors, and that to the high voltage reaction--from the second type receptors. Thus, in the frog, that is on a low phylogenetic stage, differentiation of the free bushy sensitive terminal into mechano- and chemoreceptors is already outlined.

[Structural and functional characteristics of bush-like interoceptors in the initial period of anoxia]. / Strukturno-funktsional'naia kharakteristika kustikovidnykh interotseptorov v nachal'nom periode anoksii.

The bush-like receptors of the Rana temporaria urinary bladder have been studied electrophysiologically, cytophotometrically and electronmicroscopically. A combined morpho-physiological experiment demonstrates a phase character in dynamics of the spontaneous impulsive receptor activity, no changes in the terminal plate size. heterogeneity of the reaction for methylene blue. The receptor plates have been cytophotometrically demonstrated to take a longer time for staining and bleaching; that can serve as a structural index on a decreasing energy level of metabolism. Certain changes and rearrangement in the receptors plate organelles take place. A suggestion is made that the receptors studied possess some labile enzymatic systems owing to which the metabolism level can be swiftly and profoundly changed.

[Preparation of the spinal neurons and their bushy receptors for morphophysiological study]. / Preparat dlia morfofiziologicheskogo izucheniia spinal'nykh neironov i ikh kustikovidnykh retseptorov.

A preparation of the sensory neuron of the spinal ganglion with dendritic processes for simultaneous morphological and physiological investigations is described. It consists of a frog urinary bladder with bushy interoceptors in its wall, two vesicle neurons, two abdominal branches of the X spinal nerves and two IX spinal ganglia with ventral and dorsal roots branching off from them. The total length from the receptors to the ganglion neurons is 20-30 mm. In the ganglia a zone of the neuronal bodies localization is found, their processes form receptors; the zone includes as many as 9 neurons, 50-80 mkm in size. A vital fine structure of the ganglion cells and their satellites is traced. There are three types of cells in the ganglion--large, middle and small. Electrophysiological control has demonstrated that the preparation is viable for several hours.

[Effect of sodium ion concentration on the structural and functional characteristics of bladder receptors]. / Vliianie kontsentratsii ionov natriia na strukturno-funktsional'nye kharakteristiki kustikovidnykh retseptorov.

The experiments were performed on the frog urinary bladder bushy receptors by means of a combined morpho-electrophysiological technique. Effects of decreased and increased (by 1.5 and 2 times) concentration of sodium chlorate in the alternating solution on morphological and electrophysiological characteristics of the vital receptors were investigated. Specific peculiarities of the complex morpho-physiological reaction were demonstrated at each effect studied. Analysing morphological phenomena, dynamic of spike activity and the literature data, a suggestion was made that for the receptors studied osmotic pressure fluctuations within hypotonic range serve as an adequate stimulator (besides the wall dilatation). Hypertonic medium produces a noticeable injuring effect of the receptor.

[Effect of extreme mechanical stimulation on structuro-functional changes in bushy interoceptors]. / Strukturno-funktsional'nye izmeneniia kustikovidnogo interotseptora pri ékstremal'nom mekhanicheskom razdrazhenii.

Synchronous morphophysiological reaction of intramural bushy receptors to an extreme mechanical stimulation produced by an increased pressure and hence, by an overdilatation of the urinary bladder wall has been studied in Rana temporaria. It has been demonstrated that the extreme mechanical factor inhibits the receptor spike activity. It is proved by: a decreased affinity of the receptors to vital methylene blue staining; changes in the form of the receptor patches; decreasing mobility of granules in the patches; increase in staining time. It is evident that energy exhaustion of the receptor as a result of overexcitement is responsible for these shifts. In the previous experiments an adequate (weaker) dilatation of the urinary bladder wall did not inhibit the receptor spike activity and morphological changes had different dynamics. The results of the two experiments are compared.

[Structural and functional reactive changes in the bushy interceptor of the frog urinary bladder upon adequate stimulation]. / Strukturno-funktsional'nye reaktivnye izmeneniia kustikovidnogo interotseptora mochevogo puzyria liagushki pri adekvatnom razdrazhenii.

Morphological and functional changes in the bushy receptors of the frog urinary bladder were studied after a definite cystectasia (bladder wall distention). Morphological and electrophysiological parameters were registered synchronously. Under the effect of distention the total rate of afferent impulse activity was demonstrated to increase with a simultaneous increase of the average size of the receptor end-plates and with changing (growing round) in their form. Increment of the average size of the end-plates overtakes that of the distance between two points chosen on the urinary bladder wall; certain shifts are also observed in time parameters for staining the receptors with methylene blue. A possibility is suggested on interconnections of morphological and electrophysiological shifts.

[Morphometric features of changes in the neurons of the jejunum in the aging body]. / Morfometricheskie kharakteristiki izmenenii neironov toshchei kishki v stareiushchem organizme.

It is common observation that in aged people, the number of processes in long-axonal and equal-axonal neurons decreases. Quantitative ratio of these neurons changes, as well. While at mature age long-axonal/equal-axonal ratio is 3 : 1, at old age it makes 1 : 2. In dogs, unlike in human beings, the old age influences neither the number of processes, nor the quantitative ratio of the neurons mentioned.